Ouch!

The exact same thing happened with my Dacia Jogger Extreme Hybrid. It took 3 months before the company doing the repairs were able to collect the car, which was fine as it was still driveable. It was collected about 30 days ago. They phoned a few days after collecting the car to say that the parts will have to be ordered from the manufacturer. I received a phone call today to let me know that the parts have been delivered, and that I should have the car back by the end of this week. So, according to the repair tracker:

 

Yeah, the repair company still hasn't collected my car, they're looking at a date of about 29th July. As long as the doors don't take ages to deliver, then it's fine.

 

If it's clear it's the other driver's fault then their insurer should supply an equivalent grade of car for the duration of the repair so I'd not worry too much about how long it's going to take.